GB760595A - New metallisable disazo dyestuffs - Google Patents

Abstract

The invention comprises dyestuffs which as free acids are of formula:- <FORM:0760595/IV(b)/1> where R is an aryl radicle containing at least one OH, CO2H or OCH2 CO2H group in an #sposition to the azo group, A is such a group that the coupling component HA is a nitrogen - containing heterocyclic compound capable of being metallized per se and the dyestuffs contain not more than two SO3H groups. They are made by coupling a diazo compound of an appropriate aminoazo compound with HA. The aminoazo compound may be made by coupling a diazo compound of an appropriate amine with J - acid in an aqueous alkaline medium. Specified amines are 2 - aminophenol - 4 - sulphonic acid and its 6 - chloro - derivative, 4 - chloro - 2 - aminophenol - 6 - sulphonic acid, anthranilic acid and #s - aminophenoxyacetic - acid. Specified coupling components are 8-hydroxyquinoline, 4-hydroxy -acridine and - benzthiazole, 4 - hydroxy - 2 - amino, - acetylamino - and - benzoylamino - benzthiazoles, 4 -, 5 - and 6 - hydroxyindazoles, 6 - hydroxyindazole - 4 - and - 5 - sulphonic acids, 5 - hydroxyin - dazole - 6 - and - 7 - sulphonic acids, 4 - hydroxyindazole - 6 - sulphonic acid, 1 - (5 - and 61 - indazyl) - 3 - methyl - 5 - pyrazolones and 1 - (61 - indazyl) - 3 - methyl - 5 - aminopyrazole. The dyestuffs dye cotton by an after - coppering process. Examples are provided illustrating the use of certain of the above specified components in the preparation of dyestuffs which dye cellulosic fibres in blue and red shades. In the Provisional Specification HA is any coupling components itself capable of forming complex compounds. Specifications 697,977 [Group IV (b)], 744,212 and 753,573 [Group IV(b)] are referred to.